Peel and cube one large, ripe mango or 2 small "champagne" mangos. If you can find the Champagne mangos, these are much better, not just for this recipe but for all purposes: they are sweeter and less fibrous than any other variety. There are whole instructables devoted to the subject of cutting mangos, but these instructions
are best suited for my recipe.
1/2 teaspoon calcium lactate
1-2 tablespoons sugar (depending on your taste and how ripe and sweet your mangos are)
Remove the sodium alginate bath from the fridge and pour into a shallow bowl so the the mixture comes close to the rim (this will make your job easier)
Prepare a second bowl filled with clean water nearby, and, if you are preparing this in advance, a third container with about 1 cup of mango juice.
Use a soup spoon to carefully drop a dollop (about 1/2 to 3/4 tablespoon) of the mango puree into the sodium alginate bath. You can put in 2 or maybe 3 dollops at a time, as long as you are careful not to let them touch each other. It is very hard to get a perfect sphere but don't worry, once it's on your egg it will look fine.
Use your slotted spoon to (very gently) mix the solution around the yolks so an even gel forms around each one. Leave in the bath at least 3 minutes, then, with your slotted spoon, pick them up one at a time and rinse them in your bowl of water. If you are serving immediately, proceed to step 5, otherwise after rinsing the yolks place them in some mango juice to store in the refrigerator until you are ready to serve. You can put them in water instead of juice, but depending on how long you are storing them, they will absorb some of the liquid. In water (overnight) the taste will become a bit diluted and the texture more liquid, less gooey.